Soil acidification significantly influences nitrous oxide (N₂O) emissions, with the highest emissions occurring in moderately acidic soils. A global analysis of 5438 paired data points of N₂O emission fluxes revealed a hump-shaped relationship between soil pH and emission factors (EFs), with the highest EFs in soils with pH 5.6–6.5. This is due to the dominance of N₂O-producing over N₂O-consuming denitrifying microorganisms in these conditions. The study shows that soil pH has a unimodal relationship with denitrifier communities and EFs, and that net N₂O emissions depend on both the N₂O/(N₂O + N₂) ratio and overall denitrification rate. These findings suggest that soil pH exerts a critical, nonlinear control over N₂O emissions, highlighting the need for a comprehensive understanding of pH effects on soil microorganisms and processes. The results indicate that current default EFs used in climate models may underestimate N₂O emissions, particularly in moderately acidic soils. The study also emphasizes the importance of considering soil pH in future nitrogen input scenarios to predict and mitigate N₂O emissions. The findings suggest that manipulating soil pH through liming may not be effective for N₂O mitigation due to biological and economic constraints, and that direct manipulation of N₂O-producing and consuming microbes may offer promising approaches for reducing emissions. The study provides a conceptual framework for understanding the complex relationships between soil pH, denitrification processes, and N₂O emissions, emphasizing the need for alternative strategies to reduce N₂O emissions in the context of increasing nitrogen inputs.Soil acidification significantly influences nitrous oxide (N₂O) emissions, with the highest emissions occurring in moderately acidic soils. A global analysis of 5438 paired data points of N₂O emission fluxes revealed a hump-shaped relationship between soil pH and emission factors (EFs), with the highest EFs in soils with pH 5.6–6.5. This is due to the dominance of N₂O-producing over N₂O-consuming denitrifying microorganisms in these conditions. The study shows that soil pH has a unimodal relationship with denitrifier communities and EFs, and that net N₂O emissions depend on both the N₂O/(N₂O + N₂) ratio and overall denitrification rate. These findings suggest that soil pH exerts a critical, nonlinear control over N₂O emissions, highlighting the need for a comprehensive understanding of pH effects on soil microorganisms and processes. The results indicate that current default EFs used in climate models may underestimate N₂O emissions, particularly in moderately acidic soils. The study also emphasizes the importance of considering soil pH in future nitrogen input scenarios to predict and mitigate N₂O emissions. The findings suggest that manipulating soil pH through liming may not be effective for N₂O mitigation due to biological and economic constraints, and that direct manipulation of N₂O-producing and consuming microbes may offer promising approaches for reducing emissions. The study provides a conceptual framework for understanding the complex relationships between soil pH, denitrification processes, and N₂O emissions, emphasizing the need for alternative strategies to reduce N₂O emissions in the context of increasing nitrogen inputs.